This invention relates to a system for determining a drowsy driver.
Each year numerous automotive accidents and fatalities occur as a result of sleepy individuals falling asleep while driving. It has been observed that these drivers exhibit certain physiological patterns that are predictable and detectible. The classic xe2x80x9chead bobbingxe2x80x9d motion, where the driver""s head drops and then quickly pulls back upward is one of the patterns that is often exhibited when an individual is becoming drowsy while seated in an upright position. Additionally, a drop in heart rate may also indicate the presence of a drowsy driver.
Several known drowsiness detection systems use CCD cameras or other optical sensors to detect an image of the driver""s face in order to analyze eyelid movements for signs of drowsiness. Optical sensors may become covered or blocked by dirt and debris and therefore lose their ability to function effectively. Further more, they may be ineffective when the driver is wearing eyeglasses or sunglasses.
Other systems attempt to monitor the driver""s heart rate using devices and apparatuses that must be fastened to the driver""s body. These include wrist straps, collars, headbands, glasses, and other devices. These systems may cause discomfort and may be bothersome to the driver, and therefore may place the driver at increased risk. Additionally, there is no guarantee that the driver will wear any of these devices. These systems are only effective in cases where the driver chooses to wear the device.
Furthermore, some systems attempt to detect a drowsy driver by monitoring only the steering patterns of the driver. In certain situations, these systems may incorrectly determine the driver""s drowsiness level. For example, new drivers often exhibit erratic steering patterns while learning how to drive. Also, drivers of off-road vehicles may also display abnormal and erratic steering patterns while trying to navigate rough terrain. A drowsiness detection system based solely on steering patterns may falsely identify these drivers as drowsy.
It is therefore desirable to provide an effective system capable of determining the driver""s risk of falling asleep by monitoring multiple signs of drowsiness in a redundant, reliable and non-intrusive manner that is transparent to the driver.
The drowsiness detection system includes two drowsiness detection subsystems communicating with a control unit. Using sensory fusion, intelligent fuzzy algorithms, and the sensory data, the control unit determines the drowsiness state of the driver. The system non-intrusively monitors multiple characteristics of the driver which introduces redundancy and increases the confidence level of the system""s drowsiness determination.
The first subsystem monitors the driver""s heart rate using sensors placed in the steering wheel of the vehicle. The second subsystem involves the use of an array of sensors mounted in the vehicle headliner and seat, used to detect the position of the driver""s head. The sensory data from the two subsystems is communicated to the control unit and monitored for drowsiness indicators over a period of time. Other sensors may be used alternatively or in addition to these sensors.
The control unit collects data from the entire sensory suite and improves this data using sensory fusion techniques. The control unit then uses intelligent fuzzy algorithms based on drowsiness threshold levels and patterns to make a drowsiness determination. If the driver is found to be drowsy, a signal is outputted from the control unit.